Connector assembly

ABSTRACT

In the plug connector, the front end side of a fiber optic cable used for optical signal transmission is connected to, and rearwardly extends from, the rear end side of said plug connector and lateral terminals are arranged in each of a pair of lateral edge portions that extend in the forward-backward direction; at least one of the plug connector and receptacle connector has provided therein resilient members that generate a biasing force between the plug connector and receptacle connector in the forward-backward direction; and, a restricting portion, which provides a limiting value for the distance of relative displacement of the plug connector with respect to the receptacle connector in the direction of the biasing force under the action of the above-mentioned biasing force, is formed in the receptacle connector, and a restricted portion is formed in the plug connector.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No.2019-143015, filed Aug. 2, 2019, the contents of which are incorporatedherein by reference in its entirety for all purposes.

BACKGROUND Technical Field

The present invention relates to a connector assembly comprising a plugconnector capable of converting optical signals and electrical signalsfrom one to the other and a receptacle connector with which said plugconnector is mated.

Related Art

Such a connector assembly has been disclosed, for example, in PatentReference 1. In Patent Reference 1, the plug connector (“connector 1” inPatent Reference 1) is adapted such that a fiber optic cable for opticalsignal transmission extending in a forward-backward direction parallelto the mounting surface of the circuit board is connected so as toextend rearwardly from said plug connector and optical signalstransmitted through the above-mentioned fiber optic cable are convertedto electrical signals by a light-receiving element serving as aphotoelectric conversion element incorporated into the above-mentionedplug connector. In addition to the above-mentioned photoelectricconversion element, an actuation device used to drive said photoelectricconversion element is incorporated into said plug connector, and saidactuation device is connected (interconnected) to each of a plurality ofterminals (plug terminals) with wires. Said plug terminals are arrangedin a pair of lateral edge portions that extend in the forward-backwarddirection.

When viewed in an up-down direction perpendicular to the mountingsurface of the circuit board, the size of the plug connector in theconnector width direction perpendicular both to the up-down directionand to the forward-backward direction is made larger in the front halfand smaller in the rear half. Its size in the connector width directionis differentiated by providing a stepped portion formed at the boundarybetween the front and rear halves. Terminals are arranged in the lateraledge portions of the front half, and a groove, into which the fiberoptic cable is placed, is formed in the rear half.

On the other hand, the receptacle connector (“counterpart connector 2”in Patent Reference 1) is adapted to be mounted to the mounting surfaceof the circuit board while receiving the entire above-described plugconnector from above into an upwardly open receiving recess portion suchthat the up-down direction is the direction of mating.

In the above-mentioned receiving recess portion, a space adapted forreceiving the front and rear halves of the above-mentioned plugconnector from above is formed in the interior of a perimeter wall, andan opening used for accommodating a section holding a fiber optic cableextending rearwardly from the plug connector is formed in a portion ofthe rear section of said perimeter wall. A stepped interior surfacecorresponding to the stepped portion of the plug connector is formed inthe forward-backward direction in this receiving recess portion. Such areceptacle connector comprises terminals (receptacle terminals) arrangedin a pair of lateral edge portions that extend in the forward-backwarddirection, and is electrically connected to the above-mentioned plugconnector through contact of said receptacle terminals with theabove-mentioned plug terminals. When said plug connector is mated withthe receptacle connector, the fiber optic cable is sometimes subject toa rearwardly directed tensile force and, under the action of thistensile force, the plug connector tends to move in the tensiledirection, i.e., rearwardly, through a distance corresponding to theclearance. However, the stepped portion of the plug connector abuts thestepped interior surface of the receptacle connector and the travel ofthe plug connector does not exceed the above-mentioned clearance.

PATENT REFERENCES Patent Reference 1

-   -   Japanese Unexamined Patent Application Publication No.        2012-177732

SUMMARY Problems to be Solved

In Patent Reference 1, since a stepped portion restricting the rearwardtravel of the plug connector is formed in the plug connector and astepped interior surface is formed in the receptacle connector at theboundary between the front and rear halves of the plug connector andreceptacle connector, the rearward travel of the plug connector does notexceed its clearance from the receptacle connector. However, since thepaired terminals of the plug connector and receptacle connector areplaced in contact under contact pressure, when a rearwardly directedtensile force and a forwardly directed press-fitting force repeatedlyact on the fiber optic cable, the plug connector moves back-and-forthrelative to the receptacle connector within the above-describedclearance range and the paired terminals of the plug connector andreceptacle connector repeatedly make sliding contact, thereby leading tothe generation of frictional forces between the paired terminals.

In view of these circumstances, it is an object of the present inventionto provide an electrical connector assembly in which the relativeposition of the plug connector and receptacle connector is stable, andthe generation of frictional forces between the paired terminals of thetwo connectors can be thoroughly suppressed even if a tensile force actson the fiber optic cable There is a need to provide an electricalconnector assembly in which the relative position of the plug connectorand receptacle connector is stable, and the generation of frictionalforces between the paired terminals of the two connectors can bethoroughly suppressed even if a tensile force acts on the fiber opticcable.

Technical Solution

The inventive connector assembly comprises a plug connector, whichincorporates a photoelectric conversion element capable of convertingoptical signals and electrical signals from one to the other and anactuation device used to drive said photoelectric conversion element,and a receptacle connector, with which said plug connector is mated, andthe plug connector and the receptacle connector are electricallyconnected via contact between the respective terminals.

The connector assembly according to the present invention ischaracterized by the fact that, in the plug connector, the front endside of a fiber optic cable used for optical signal transmission isconnected to, and rearwardly extends from, the rear end side of saidplug connector and lateral terminals are arranged in each of a pair oflateral edge portions that extend in the forward-backward direction; atleast one of the plug connector and receptacle connector has providedtherein resilient members that generate a biasing force between the plugconnector and receptacle connector in the forward-backward direction;and a restricting portion, which provides a limiting value for thedistance of relative displacement of the plug connector with respect tothe receptacle connector in the direction of the biasing force under theaction of the above-mentioned biasing force, is formed in the receptacleconnector, and a restricted portion is formed in the plug connector.

In the thus-configured present invention, a restricting portion isprovided in the receptacle connector and a restricted portion isprovided in the plug connector. Meanwhile, at least one of the plugconnector and receptacle connector has provided therein resilientmembers applying rearward pressure to the plug connector so as togenerate a biasing force between the plug connector and receptacleconnector, and the plug connector is constantly rearwardly biased by theresilient members. Therefore, the terminals of the plug connector andreceptacle connector are placed in contact in a stable position suchthat even if there is clearance between the plug connector andreceptacle connector, the paired terminals of the two connectors aremaintained in the above-mentioned stable position and no friction due tothe above-mentioned clearance is produced.

In the present invention, the above-mentioned resilient members may beresilient end terminals arranged in the front end edge portion of theplug connector or receptacle connector located on the front end side andextending in a direction perpendicular to said forward-backwarddirection. By providing the end terminals as resilient members, thetotal number of terminals can be increased in exact proportion to thenumber of end terminals used in addition to the lateral terminalswithout increasing connector dimensions, and contact pressure can alsobe naturally achieved due to the resilience of the end terminals.

In the present invention, a direction perpendicular to the planecomprising the array direction of the above-mentioned resilient endterminals and the array direction of the above-mentioned lateralterminals of the above-mentioned plug connector can be used as thedirection of mating of the above-mentioned plug connector and theabove-mentioned receptacle connector. Using a direction perpendicular tothe plane comprising the array direction of the lateral terminals andthe array direction of the resilient end terminals as the direction ofconnector mating facilitates mating and makes forming the restrictingand restricted portion easier.

Technical Effect

In the present invention, as described above, at least one of the plugconnector and receptacle connector has provided therein resilientmembers that generate a biasing force between the plug connector andreceptacle connector in the forward-backward direction. Meanwhile, arestricting portion, which provides a limiting value for the distance ofrelative displacement of the plug connector with respect to thereceptacle connector in the direction of the biasing force under theaction of the above-mentioned biasing force, is formed in the receptacleconnector, and a restricted portion is formed in the plug connector. Forthis reason, the plug connector is constantly rearwardly biased by thebiasing force of the resilient members and, even if there is a clearancebetween the plug connector and receptacle connector, the pairedterminals of the plug and receptacle connectors are placed in contact ina stable position.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1 (A) and 1 (B) illustrate a perspective view illustrating a statein which connector assemblies representing an embodiment of the presentinvention are provided in each of a signal processing portion containedin an electronic device and measurement portions extending from saidelectronic device, wherein FIG. 1 (A) is a perspective view, and FIG. 1(B) is a lateral view.

FIGS. 2 (A) and 2 (B) are perspective views illustrating a singleconnector assembly of FIG. 1 (A) and FIG. 1 (B), wherein FIG. 2 (A) is astate before mating the plug connector with the receptacle connector,and FIG. 2 (B) is a state is after mating.

FIG. 3 illustrates a perspective view illustrating the plug connector ofFIG. 2 (A) in a vertically flipped orientation.

FIG. 4 (A) and FIG. 4 (B) illustrate vertical cross-sectional views ofthe plug connector of FIG. 3, wherein FIG. 4 (A) illustrates the plugconnector in its entirety, and FIG. 4 (B) is an enlarged view of oneportion thereof.

FIG. 5 illustrates a plan view illustrating the positional relationshipof the support member of the plug connector and the photoelectricconversion element supported on said support member, the actuationdevice, as well as the lateral terminals and end terminals.

FIGS. 6 (A) and 6 (B) are an illustration of the procedure used to matethe plug connector with the receptacle connector, wherein FIG. 6 (A)illustrates only the plug connector with a vertical cross-section takenin the vicinity of a lateral edge of the plug connector and shows thereceptacle connector with a lateral view in a state when, prior tomating, the plug connector is in a tilted orientation, and FIG. 6 (B) isa vertical cross-sectional view taken in the vicinity of a lateral edgeof the plug connector at the start of fitting when only the front endportion of the plug connector has been fitted in.

FIG. 7 illustrates a vertical cross-sectional view taken in a planeextending in the connector width direction at the location of thelateral terminals in a state in which the plug connector has been matedwith the receptacle connector.

FIGS. 8 (A) and 8 (B) illustrate vertical cross-sectional views of thefront end portion taken in a plane extending in the forward-backwarddirection in a state in which the plug connector has been mated with thereceptacle connector, wherein FIG. 8 (A) is a vertical cross-sectionalview taken in the vicinity of a lateral edge of the plug connector inthe connector width direction, and FIG. 8 (B) is a verticalcross-sectional view taken at the location of the end terminal in theconnector width direction.

FIG. 9 illustrates a perspective view illustrating an example in whichmultiple connector assemblies are disposed on a circuit board.

FIG. 10 illustrates a front elevation view illustrating the placement ofthe connector assemblies of FIG. 9.

FIGS. 11 (A) and 11 (B) illustrate perspective views of a variation ofthe present invention prior to the mating of the plug connector and thereceptacle connector.

FIG. 12 (A) is a cross-sectional view taken at the start of mating, inwhich only the front end portion of the plug connector has been fittedinto the receptacle connector, and FIG. 12 (B) is a cross-sectional viewtaken in a mated state.

DETAILED DESCRIPTION

FIG. 1 (A) is a perspective view illustrating a state in which connectorassemblies representing an embodiment of the present invention areprovided in each of a signal processing portion contained in anelectronic device (not shown) and measurement portions extending fromsaid electronic device, and FIG. 2 (B) is a side view thereof.

FIG. 1 (A) and FIG. 1 (B) illustrate a signal processing portion Icontained in an electronic device and measurement portions II extendingfrom said electronic device. Said electronic device and the measurementportions II are used to form, for example, an endoscope system in whichcase the electronic device constitutes the main body portion of theendoscope system and the measurement portions II constitute anendoscope.

The signal processing portion I, which is adapted to convert opticalsignals received from the measurement portions II via fiber optic cablesF to electronic signals and process them, has disposed on circuit boardP a plurality of connector assemblies 1 used for optical signalreception and conversion to electrical signals, and a processor 2, whichserves as a signal processing unit that processes electrical signalsobtained from the connector assemblies 1.

In the example illustrated in FIG. 1 (A), two assemblies are disposed onthe top face of circuit board P and two are disposed on its bottom face(the lower connector assemblies are obscured by the circuit board P inFIG. 1 (A) and not shown, but are shown in FIG. 1 (B)). Theabove-mentioned connector assemblies 1 have a plug connector 3, to whicha fiber optic cable F is connected, and a receptacle connector 4, towhich said plug connector 3 is matingly connected. The plug connector 3and the receptacle connector 4 will be described in detail below.

The fiber optic cable F, whose front end side is connected to the rearend side of the plug connector 3, is a single, single-fiber, fiber opticcable. In addition, a single connector assembly 1 is formed by the plugconnector 3, to which this single fiber optic cable is connected, andthe receptacle connector 4, to which said plug connector 3 is matinglyconnected. In the present embodiment, disposing the connector assemblies1 on both faces of circuit board P provides freedom in making changes tothe number of, and in selecting placement locations for, the singleconnector assemblies 1, thereby making it possible to efficientlyutilize both faces of the circuit board.

As can be seen in FIG. 1 (A) and FIG. 1 (B), the measurement portionsII, which extend from the signal processing portion I, have cameras 12serving as measurement elements and connector assemblies that arecompletely identical to the above-described connector assemblies 1disposed, as relay elements, on a circuit board Q inside a flexibleguard 11 (therefore, in FIG. 1 (A) and FIG. 1 (B), the connectorassemblies on circuit board Q are also shown as connector assemblies 1).In the present embodiment, as shown in FIG. 1 (A), there are providedtwo measurement portions II, however the illustration of one flexibleguard 11 has been omitted in the drawing such that the internal cameras12, connector assemblies 1, and circuit board Q are shown exposed (inFIG. 1 (B), the illustration of the flexible guards 11 has beenomitted).

In FIG. 1 (A) and FIG. 1 (B), the cameras 12 are disposed on each of thetop and bottom faces of circuit board Q inside each flexible guard 11 inthe measurement portion II and aiming the distal end of one flexibleguard 11 at the site of measurement makes it possible to perform imagingusing the two cameras 12. The upper and lower cameras 12 are connectedrespectively to the upper and lower connector assemblies 1 and the fiberoptic cables F extending from the upper and lower connector assemblies 1are connected respectively to the upper and lower connector assemblies 1on circuit board P in the signal processing portion I.

Optical signals obtained by imaging with the cameras 12 are changed intoelectrical signals in the cameras 12 and said electrical signals aresent to the plug connectors 3 through the receptacle connectors 4 of theconnector assemblies 1 on circuit board Q. The above-mentionedelectrical signals are converted to optical signals by photoelectricconversion elements in the plug connectors 3 and these optical signalsare sent via the fiber optic cables F to the connector assemblies 1 oncircuit board P of the signal processing portion I.

The aforementioned connector assemblies 1 used in the signal processingportion I and the measurement portions II will be described next.Connector assemblies 1 of exactly the same configuration are used bothin the signal processing portion I and in the measurement portions II,with the only difference between the two being the direction of signalconversion. In the former, optical signals are converted to electricalsignals, whereas electrical signals are converted to optical signals inthe latter. Since there isn't any substantial difference in theirconfigurations, the discussion herein will thus focus on the connectorassemblies 1 in the signal processing portion I.

As can be seen in FIG. 2 (A) and FIG. 2 (B), the plug connector 3 andreceptacle connector 4 constituting the connector assemblies 1 areadapted to be matingly connected in the direction of mating Z, which isa direction perpendicular to the surface of circuit board P. In FIG. 2(A) and FIG. 2 (B), the plug connector 3 is mated with the receptacleconnector 4 from above and is removed therefrom in the upward direction.FIG. 2 (A) illustrates a state before mating and FIG. 2 (B) illustratesa state after mating.

As can be seen in FIG. 2 (A), the fiber optic cable F of the plugconnector 3 is connected in the forward-backward direction X that isparallel to the surface of circuit board P and perpendicular to theabove-mentioned mating direction Z so as to extend from the rear endside of said plug connector 3. The dimensions of the front half 31 ofthe plug connector 3 in the connector width direction Y (directionperpendicular to both the forward-backward direction X and the matingdirection Z) are formed to be larger than those of the rear half 32.

Terminals 5 are arranged in the front half 31 so as to be exposed on theexterior peripheral surface of the front half 31. Specifically, in eachof a pair of lateral edge portions 33 located so as to be opposed in theconnector width direction Y and extending in the forward-backwarddirection X, there are arranged lateral terminals 51, which are exposedon the exterior lateral faces of said lateral edge portions 33, and, inthe front end edge portion 34 that extends in the connector widthdirection Y, there are arranged end terminals 52, which are exposed onthe exterior lateral face of said front end edge portion 34. Inclinedprotrusions 35 are formed in the corner portions where the lateral edgeportions 33 and the front end edge portion 34 intersect. These inclinedprotrusions 35, which protrude from the exterior lateral faces of thelateral edge portions 33 and from the front end face of the front endedge portion 34, have inclined top faces 35A and inclined bottom faces35B that are downwardly tilted from back to front. The inclined topfaces 35A and inclined bottom faces 35B are in substantially parallelplanes. Restricted portions 35A-1, which extend a short distanceperpendicularly to the mounting surface of circuit board P, that is, inthe mating direction Z, are formed in the sections below the lower endsof the inclined top faces 35A, and restricted portions 35B-1, whichextend a short distance in the mating direction Z, are formed in thesections above the upper ends of the inclined bottom faces 35B. Saidrestricted portions 35B-1 abut the restricting portions of thehereinafter-described receptacle connector 4, thereby restrictingrearward movement in the forward-backward direction X. A forwardlyprotruding front tab 36 that extends in the connector width direction Yis provided in the upper front end portion of the front half 31 of theplug connector 3.

The rear half 32 of the plug connector 3 has formed therein recesses32A, whose width dimensions are made smaller than those of the fronthalf 31 in the connector width direction Y, and protruding portions 32B,whose width dimensions are made the same as those of the front half 31,are provided rearwardly of these recesses 32A. Shallow engagementgrooves 32A-1, which extend all the way to the upper ends of therecesses and approach the vicinity of their lower ends, are formed inthe recesses 32A.

The interior of this plug connector 3 will be described further afterthe following discussion of the receptacle connector 4 providedhereinbelow.

The receptacle connector 4, with which the above-described plugconnector 3 is mated from above, has a receiving recess portion 4A forreceiving the plug connector 3 that is formed by a perimeter wall 61 anda bottom wall 60, and the perimeter wall 61 has a pair of lateral walls62, a front end wall 63, and rear end walls 64. The interior surface ofthe perimeter wall 61 forming the receiving recess portion 4A is formedto a shape and dimensions suitable for receiving the front half 31 ofthe plug connector 3 from above.

Terminal grooves 62A are formed in the lateral walls 62, and attachedthereto are resilient lateral terminals 65 (hereinafter referred tosimply as “lateral terminals 65”), which are placed in contact with thelateral terminals 51 of the plug connector 3. Resiliently deformablecontact portions 65A protruding on the interior surface side of thelateral walls 62 are provided in said lateral terminals 65 so as toprotrude from the interior surface of the lateral walls 62, andconnecting portions 65B bent in an L-shaped configuration are providedon the exterior surface side of the lateral walls 62 at the lower end ofthe lateral walls 62 in contact with the surface of circuit board P.

The lateral walls 62 have lead-in recesses 62B formed on the interiorsurface between the front end wall 63 and the ranges of the lateralterminals 65 (in other words, between the front end wall 63 and thelateral terminals 65 located in the forward-most position). Said lead-inrecesses 62B are formed as upwardly open recesses on the interiorsurface of the lateral walls 62 and serve as spaces into which theinclined protrusions 35 of the plug connector 3 are introduced fromabove. On the rear wall surface of said lead-in recesses 62B, there areformed restricting portions 62B-1 which, by abutting the restrictedportions 35B-1 of the inclined protrusions 35, restrict the rearwardmovement of the plug connector 3 to which a biasing force is applied bythe contact portions 66A of the hereinafter-described end terminals 66.Specifically, said restricting portions 62B-1 are adapted to provide alimiting value for the distance of relative displacement of the plugconnector 3 under the action of the above-mentioned biasing forcerelative to the receptacle connector 4 in the direction of the biasingforce (rearward).

Terminal grooves 63A, which are similar to the terminal grooves 62A inthe lateral walls 62, are formed in the front end wall 63, and resilientend terminals 66 (hereinafter referred to simply as “end terminals 66”),which are similar to the lateral terminals 65, are attached to saidterminal grooves 63A. In the same manner as the lateral terminals 65,these end terminals 66 also have resilient contact portions 66A providedon the interior surface side of the front end wall 63 (in FIG. 2 (A)said contact portions 66A are located on the interior surface side ofthe front end wall 63 and not shown), and connecting portions 66B areprovided on the exterior surface side of the front end wall 63. When theplug connector 3 is mated with the receptacle connector 4, said endterminals 66 serve as resilient members whose contact portions 66A areheld in resilient contact with the end terminals 52 of the plugconnector 3, and said contact portions 66A apply a rearwardly directedbiasing force to the plug connector 3. If the end terminals 66 are notrequired, the resilient members can be implemented not as end terminalshaving resilient contact portions, but as resilient members of adifferent type.

In the present embodiment, as previously discussed, in the plugconnector 3, lateral terminals 51 are arranged in the lateral edgeportions and end terminals 52 are arranged in the front end edgeportion. In addition, in the receptacle connector 4, lateral terminals65 are arranged on the lateral walls 62 and end terminals 66 arearranged on the front end wall 63. Therefore, in comparison with theprior-art connector assemblies provided only with lateral terminals, thenumber of terminals can be increased in exact proportion to the numberof end terminals without increasing connector dimensions.

In addition, since the end terminals 66 are arranged on the front endwall 63 of the receptacle connector 4, circuitry S used to electricallyconnect said end terminals 66 and the processor 2 may be formed on themounting surface of circuit board P in the forward-backward direction Xtowards the processor 2 (see FIG. 9), and said circuitry S can be formedin a simple shape by keeping it short and straight.

The front end wall 63 has an increasing wall thickness throughout thearray range of the end terminals 66 extending in the connector widthdirection Y, and its upper inner edge has formed thereon inclined faceportions 63B that slope inwardly and downwardly. When the plug connector3 that has been mated with the receptacle connector 4 is removed bytilting so as to raise the rear end side (side from which the fiberoptic cable F extends) while using the front end side as a fulcrum, saidinclined face portions 63B have the front end of the front tab 36 of theabove-mentioned plug connector 3 abutting against them and serve as theabove-mentioned fulcrum.

In comparison with the lateral walls 62 and the front end wall 63, therear end walls 64 are formed to be of greater wall thickness (dimensionsin the forward-backward direction X) and, as a result of cutting out anintermediate area in the connector width direction Y, there is formed apass-through groove 67 that is upwardly open in the direction of matingZ while extending in the forward-backward direction X. This pass-throughgroove 67 forms a space into which the section comprising the recesses32A formed in the rear half of the plug connector 3 can be nested fromabove. Consequently, when the plug connector 3 is in a mated state, theprotruding portions 32B located rearward of the recesses 32A of the plugconnector 3 are located externally of the receptacle connector 4.

As a result of forming the pass-through groove 67 extending in the wallthickness direction (forward-backward direction X in FIG. 2 (A)), therear end walls 64 remain in a spaced-apart relationship in the connectorwidth direction Y on both sides of the pass-through groove 67. Fastenerholding grooves 68, which are produced by recessing the exteriorsurfaces (interior lateral face, exterior lateral face, and top face) ofthe rear end walls 64, are formed in each of the opposed rear end walls64, and fasteners 69 are attached to these fastener holding grooves 68.

The fasteners 69 have substantially horizontal S-shaped cross-sectionsin a plane perpendicular to the forward-backward direction X (Y-Z plane)and, in the connector width direction Y, have fastening pieces 69A,which are located on the exterior lateral faces of the fastener holdinggrooves 68, and engagement pieces 69B, which are located on the interiorlateral faces of the fastener holding grooves 68. The fastening pieces69A, which are mated with the exterior lateral faces of the rear endwalls 64 from above, have fastening portions 69A-1 solder-attached tocircuit board P at the lower end thereof, and the engagement pieces 69Bhave engagement protrusions 69B-1 that possess resilience in theconnector width direction Y and are bent so as to protrude in the samedirection. Said engagement protrusions 69B-1 engage with the engagementgrooves 32A-1 of the plug connector 3, thereby preventing upward removalof the plug connector 3.

In this manner, as depicted in FIG. 2 (B), the plug connector 3 iscontained within the receiving recess portion 4A of the receptacleconnector 4.

While the description of the plug connector 3 with reference to FIG. 2(A) has focused on the top face and lateral face sides of said plugconnector 3, the following discussion will focus on the bottom face sideof said plug connector 3 and its interior.

FIG. 3 is a perspective view illustrating the appearance of the bottomface side, in which the plug connector 3 of FIG. 2 (A) is shown in avertically flipped orientation, FIG. 4 (A) is a vertical cross-sectionalview taken in a plane comprising the axes of the fiber optic cables F(X-Z plane), and FIG. 4 (B) is a partial enlarged view thereof.

As can be seen in FIG. 3 and FIG. 4 (A), a fiber optic cable F isconnected to the plug connector 3. The fiber optic cable F connected tothe plug connector 3 is itself quite well-known and, as can be seen inFIG. 3 and FIG. 4 (A), has a fiber optic filament F1 (hereinafterreferred to as “filament F1”), which is made by covering a glass corewith a glass cladding, and a coating F2 made of resin or the like, whichcovers said filament F1. As can be seen in FIG. 3 and FIG. 4 (A), in thepresent embodiment, the coating F2 has been removed from the front endportion of the above-mentioned fiber optic cable F and the filament F1is exposed.

As can be seen in FIG. 4 (A) and FIG. 4 (B), the plug connector 3 hasvarious elements including a photoelectric conversion element 20, whichserves as an optical semiconductor element used to convert opticalsignals and electrical signals from one to the other, an actuationdevice 21, which drives the photoelectric conversion element 20, asupport member 22, which supports said photoelectric conversion element20 and the actuation device 21, and multiple lateral terminals 51 andend terminals 52 serving as contact members respectively contacting thelateral terminals 65 and end terminals 66 of the counterpart receptacleconnector 4 (see FIG. 1 (A) and FIG. 1 (B)). All these elements aresecured in place by integral molding using a first resin member R1 and asecond resin member R2, which will be described below. After molding thefirst resin member R1, the second resin member R2 is molded on top ofit, thereby forming the general configuration of the housing of the plugconnector 3. As a result, a front half 31 and a rear half 32 are formed.As can be seen in FIG. 4 (A), the first resin member R1 is locatedsubstantially within the range of the front half 31, and the secondresin member R2, while surrounding said first resin member R1, is alsolocated in the rear half 32.

As can be seen in FIG. 5, which illustrates the positional relationshipof the photoelectric conversion element 20, actuation device 21, supportmember 22 as seen from above, as well as the lateral terminals 51 andend terminals 52, the photoelectric conversion element 20 and theactuation device 21, as well as the actuation device 21 and the lateralterminals 51 and end terminals 52 are interconnected by wires 23 thatserve as electrically conductive members. In FIG. 4 (A), thephotoelectric conversion element 20, actuation device 21, support member22, lateral terminals 51, end terminals 52, and wires 23 are secured inplace by integral molding using the first resin member R1, which is madeof transparent resin, and the second resin member R2, which is made ofnon-translucent resin and is molded integrally with the exterior surfaceof said first resin member R1. As discussed above, in the presentembodiment, said first resin member R1 and second resin member R2 formthe housing of the plug connector 3.

The photoelectric conversion element 20 is a surface light-receivingelement (e.g., a photodiode (PD)) that converts optical signals toelectrical signals in the connector assemblies 1 disposed on circuitboard P in FIG. 1 (A) and FIG. 1 (B). As can be seen in FIG. 4 (A) andFIG. 4 (B), said photoelectric conversion element 20 is mounted to thehereinafter-described support member 22 while being oriented such thatits light-receiving surface is facing upward. The actuation device 21 isa device driving the photoelectric conversion element 20 (e.g., atransimpedance amplifier/limiting amplifier (TIA/LA)). Said actuationdevice 21, which is mounted to the hereinafter-described support member22, is located forward of the photoelectric conversion element 20 and isconnected to said photoelectric conversion element 20 by wires 23 (seeFIG. 5).

In the connector assemblies 1 on circuit board P in FIG. 1 (A) and FIG.1 (B), the plug connector 3, as previously discussed, is a connectorthat converts optical signals to electrical signals and has alight-receiving element serving as a photoelectric conversion element20. Meanwhile, in the connector assemblies 1 on circuit board Q in FIG.1 (A) and FIG. 1 (B), the plug connector 3 is a connector that convertselectrical signals to optical signals. In such a plug connector 3 thatconverts electrical signals to optical signals, an optical semiconductorelement such as a surface-emitting light-emitting element (for example,a vertical cavity surface-emitting laser (VCSEL) type light-emittingelement) is provided as the photoelectric conversion element 20. In thiscase, an actuation device used to drive the above-mentionedlight-emitting element (for example, a VCSEL driver) is provided as theactuation device 21.

The support member 22 is fabricated by stamping out from a metal platealong with the lateral terminals 51 and end terminals 52. As can be seenin FIG. 5, the lateral terminals 51 and end terminals 52 are arrangedalong each of the three perimeter edges (i.e., the end and lateraledges) of the front half of the support member 22 (left half in FIG. 5).The lateral terminals 51 include one pair of grounding lateral terminals51G and nine pairs of signal lateral terminals 51S located along thelateral edges 22A of the support member 22 so as to form pairs ofterminals located on the upper and lower lateral edges 22A of thesupport member 22 illustrated in FIG. 5. The signal lateral terminals51S are spaced apart from the lateral edges 22A of the support member 22and the grounding lateral terminals 51G are coupled to the lateral edges22A of the support member 22. The end terminals 52 include a pair ofadjacent signal end terminals 52S, which are arranged along the frontend edge 22B of the support member 22 (left edge in FIG. 5), andgrounding end terminals 52G located on both sides thereof. The signalend terminals 52S are spaced apart from the front end edge 22B of thesupport member 22 and the grounding end terminals 52G are coupled to thefront end edge 22B of the support member 22. The rear half of thesupport member 22 (right half in FIG. 5) constitutes a supported portion26 supported by the hereinafter-described second resin member R2.

In the present embodiment, if the terminals 5 are adapted to handlehigh-speed signals, both the signal lateral terminals 51S and the signalend terminals 52S can be used as differential terminals. As far as thesignal lateral terminals 51S are concerned, a pair of signal lateralterminals 51S opposed in the connector width direction Y are used as apair of signal-type differential terminals, such that nine pairs ofsignal-type differential terminals are obtained in the case illustratedin the drawings. Locating the paired signal lateral terminals 51S ineach pair symmetrically in the connector width direction Y makes itpossible to equalize the interconnection lengths to the actuation device21 by the wires 23 and form paths for signal transmission under the sameconditions, which is more suitable for differential signals. Further, asfar as the signal end terminals 52S are concerned, a pair of twoadjacent signal end terminals 52S can be used as differential terminalsand, in such a case, the interconnections to the actuation device 21 aremutually parallel, thereby making it possible to equalize the lengths ofthe interconnections and form paths for signal transmission under thesame conditions, which is more suitable for differential signals. Inother words, excellent signal transmission quality can be ensured bymaking the strength of coupling between the differential signals flowingthrough the differential terminals sufficiently large.

In the manufacturing process, although the support member 22, along withthe lateral terminals 51 and end terminals 52, is fabricated by stampingout from a metal plate, during the stamping operation, the supportmember 22, along with the lateral terminals 51 end terminals 52, isobtained as a semi-finished support member (not shown) coupled throughthe medium of a carrier section (not shown). Specifically, thissemi-finished support member has a carrier section (not shown) thatencloses the end terminals 52, lateral terminals 51, and support member22 illustrated in FIG. 5, and the lateral terminals 51 and end terminals52 are coupled to said carrier section.

Within the bounds of the front half of the support member 22, theactuation device 21 and photoelectric conversion element 20 located onthe support member 22, as well as the lateral terminals 51 and endterminals 52 surrounding the support member 22, are molded integrallywith the front half of the support member 22 using the first resinmember R1 in a state in which the lateral terminals 51 and end terminals52 are connected to the actuation device 21 on the semi-finished supportmember by the wires 23, and the actuation device 21 is connected to thephotoelectric conversion element 20 by the wires 23. Subsequently, saidfirst resin member R1 is secured in place via integral molding with thesupported portion 26 of the support member 22 using the second resinmember R2. Said second resin member R2 has a V-shaped retaining grooveR2A upwardly open in FIG. 3 (downwardly open and not shown in FIG. 1 (A)and FIG. 1 (B)) formed throughout the extent of the supported portion 26and its rearward extent, and the fiber optic cable F is secured in placewithin this retaining groove R2A with its coating F2.

As shown in FIG. 4 (A) and FIG. 4 (B), an upwardly open groove portionR1A is formed in the first resin member R1 and an upwardly raised ridgeportion R1B is formed within said groove portion R1A. The rear surfaceof said ridge portion R1B is in a plane perpendicular to theforward-backward direction X, and the front end face of the filament F1of the fiber optic cable F is in surface contact therewith.

In addition, the front surface of said ridge portion R1B is formed so asto have an exterior surface convexly curved throughout a forwardly andupwardly extending range, and this convexly curved exterior surface, inother words, the concavely curved interior surface, functions as areflective surface R1C used to change the light path by reflectingoptical signals from the fiber optic cable F. As can be seen in FIG. 4(A) and FIG. 4 (B), said reflective surface R1C is located above thephotoelectric conversion element 20 and, as shown by the light pathillustrated in FIG. 4 (B) with a dashed line, optical signalspropagating forward from the front end face of the filament F1 of thefiber optic cable F through the ridge portion R1B are reflected by thereflective surface R1C such that the optical path is deflecteddownwardly and the signals are focused on the light-receiving surface(top face) of the photoelectric conversion element 20.

The second resin member R2 made of non-translucent resin has asubstantially rectangular parallelepiped-like external configurationand, as can be seen in FIG. 3, etc., reaches the rear half 32 locatedrearward of the first resin member R1. The contact portions of both thesignal lateral terminals 51S and the grounding lateral terminals 51G oflateral terminals 51 are exposed on the exterior lateral faces thatextend in the forward-backward direction X (exterior lateral faces ofthe lateral edge portions 33). In addition, the contact portions of boththe signal end terminals 52S and the grounding end terminals 52G of theend terminals 52 are exposed on the front end face that extends in theconnector width direction Y (front end face of the front end edgeportion 34).

The procedure for matingly connecting the thus-configured plug connector3 to the receptacle connector 4 will be discussed next.

Although the plug connector 3 is mated with the receptacle connector 4from above in an orientation parallel to the receptacle connector 4, inmany cases, such a parallel orientation is not used, and, as can be seenin FIG. 6 (A) and FIG. 6 (B), the front end side of the plug connector 3(left-hand side in FIG. 6 (A) and FIG. 6 (B)) may sometimes be nestedinto the receptacle connector 4 first in an orientation in which thisfront end side is tilted downward, whereupon the rear end side may belowered and mating finally completed in the above-mentioned parallelorientation. If mating is performed in accordance with such a procedure,the advantage is that positioning is made easier because the front endside is first nested locally.

First, as can be seen in FIG. 6 (A), the plug connector 3 is placed in alocation above the receptacle connector 4 and oriented such that thefront end portion is tilted downward. In other words, it is orientedsuch that the rear end side from which the fiber optic cable F extendsis tilted upward.

Next, with its front end portion still tilted downward, the plugconnector 3 is lowered and the front end portion is first nested intothe receptacle connector 4. The front end portion has formed thereininclined protrusions 35, and said inclined protrusions 35, as discussedabove, protrude both from the exterior lateral faces 33 and the frontend face 34 of the plug connector 3 (see FIG. 2 (A)). As depicted inFIG. 6 (A), in comparison with the orientation in which the fiber opticcable F connected to the plug connector 3 extends horizontally(non-inclined orientation illustrated in FIG. 2 (A)), in the orientation(inclined orientation) in which the front end portion of the plugconnector 3 is tilted downward, the inclined protrusions 35 assume anorientation in which the surfaces of the inclined top faces 35A and theinclined bottom faces 35B of the inclined protrusions 35, when viewed inthe connector width direction Y, become closer to the up-down direction(mating direction Z), which is more suitable for nesting into thereceptacle connector 4. Therefore, as depicted in FIG. 6 (B), when theplug connector 3 is lowered, the inclined protrusions 35 are guided intothe lead-in recesses 62B of the receptacle connector 4 and, as a result,the plug connector 3 is placed in a position for mating with thereceptacle connector 4 both in the forward-backward direction X and inthe connector width direction Y.

In this state, by lowering the rear end side of the plug connector 3,that is, the side from which the fiber optic cable F extends, androtating it clockwise about the front end portion of the plug connector3, mating with the receptacle connector 4 is increased and completed ata predetermined depth extending throughout the entire length of the plugconnector 3.

In the process of rotation about the front end portion of the plugconnector 3 from the start of nesting of the inclined protrusions 35into the lead-in recesses 62B until completion of mating of the plugconnector 3 with the receptacle connector 4, the lateral terminals 51 ofthe plug connector 3 are in sliding contact with the resilient contactportions 65A of the lateral terminals 65 of the receptacle connector 4while maintaining contact pressure against said contact portions 65A. Atsuch time, the lateral terminals 51 make sliding contact with thelateral terminals 65 substantially in the direction of mating Z and makealmost no sliding contact therewith in the forward-backward direction X.Consequently, there is no scratching between the lateral edges of thelateral terminals 51 of the plug connector 3 and the lateral terminals65 of the receptacle connector 4, and, as a result, the two connectorsare mated smoothly and easily, and the paired terminals are brought intocontact as shown in FIG. 7. In addition, since in the process of theabove-described rotation the end terminals 52 of the plug connector 3and the end terminals 66 of the receptacle connector 4 are brought intocontact while their surfaces approach one another, no sliding contacttakes place.

As can be seen in FIG. 8 (A), once the mating of plug connector 3 to thepredetermined depth is complete, the inclined protrusions 35 of the plugconnector 3 assume an inclined orientation in the lead-in recesses 62Bof the receptacle connector 4. As a result, the inclined protrusions 35have their front restricted portions 35A-1 placed in a face-to-facerelationship with the front interior surfaces of the lead-in recesses62B and their rear restricted portions 35B-1 in a face-to-facerelationship with the restricting portions 62B-1 formed on the rearinterior surface of the lead-in recesses 62B, thereby restricting theposition of the plug connector 3 in the forward-backward direction X.

As can be seen in FIG. 8 (A), the maximum dimension of the inclinedprotrusions 35 in the forward-backward direction X (distance between therestricted portions 35A-1 and the restricted portions 35B-1) is slightlysmaller than the dimensions of the lead-in recesses 62B in theforward-backward direction X. In other words, there is some clearance(spacing) between the restricted portions 35A-1, 35B-1 and the lead-inrecesses 62B in the forward-backward direction X. Since in the presentembodiment, as can be seen in FIG. 8 (B), the resilient contact portions66A of the end terminals 66 of the receptacle connector 4 abut the endterminals 52 of the plug connector 3 from the front, the plug connector3 is subject to a constant biasing force directed rearwardly from saidcontact portions 66A. As a result, as can be seen in FIG. 8 (A), a stateis maintained in which the rear restricted portions 35B-1 of theinclined protrusions 35 abut the restricting portions 62B-1 formed onthe rear interior surface of the lead-in recesses 62B. Therefore, evenif a random rearwardly directed pulling force should act on the fiberoptic cable F in the mated state of the connectors, the lateralterminals 51 of the plug connector 3 and the lateral terminals 65 of thereceptacle connector 4 will maintain a state of contact in a stablerelative position and generation of frictional forces in theforward-backward direction due to the above-mentioned clearance will beadequately suppressed.

The procedure used for removing the plug connector 3 from the receptacleconnector 4 will be discussed below. In order to remove the plugconnector 3 from the receptacle connector 4, the rear end side of theplug connector 3, i.e., the side from which the fiber optic cable Fextends, is raised and the plug connector 3 is tilted. At such time, thefront tab 36 located on the front end side of the plug connector 3 abutsthe inclined face portions 63B formed on the interior top face of thefront end wall 63 of the receptacle connector 4 and the plug connector 3rotates using the points of abutment between the front tab 36 and theinclined face portions 63B as fulcra such that the tilt of said plugconnector 3 is readily increased and its removal becomes possible, asdepicted in FIG. 6 (B). Since the inclined protrusions 35 of the plugconnector 3 remain within the lead-in recesses 62B of the receptacleconnector 4 in the process of rotation of the plug connector 3, the plugconnector 3 can be reliably rotated while preventing the front tab 36from being rearwardly detached from the inclined face portions 63B.

As can be seen in FIG. 9 and FIG. 10, multiple connector assemblies 1 ofthe present embodiment provided with a plug connector 3 and a receptacleconnector 4 can be disposed both on the top and bottom faces of circuitboard P (and furthermore, on circuit board Q). In the presentembodiment, as can be seen in FIG. 10, the connector assemblies 1 aredisposed in locations that are mutually offset in the connector widthdirection Y on the top and bottom sides of circuit board P; when viewedin the forward-backward direction X, they are disposed in a staggeredmanner. Along with making efficient use of both faces of circuit board Pand allowing for each connector assembly 1 to be disposed in appropriatelocations suitable for routing to the processor 2, etc., such placementallows for an arbitrary number of multiple connector assemblies 1 to beplaced in a compact manner.

In addition, disposing the connector assemblies 1 in a staggered manneras described above makes it possible, for example, to form vias used toconnect the processor 2 and the connector assemblies 1 disposed on thebottom face of circuit board P (not shown) so as to extend from thebottom face to the top face of circuit board P. As a result, for all theconnector assemblies 1 disposed on circuit board P, it is sufficient toform circuitry used for connection to the processor 2 only on the topface of circuit board P, which facilitates the design of said circuitry.

Although in the present embodiment there are two connector assemblies 1disposed on the surface of each of the top and bottom faces of circuitboard P, as an alternative, the effect of facilitating the design of theabove-described circuitry is obtained if, along with disposing multipleconnector assemblies on the surface of one of the top and bottom faces,at least one connector assembly is disposed on the other face, and theconnector assemblies on the top and bottom faces, when viewed in theforward-backward direction X, are disposed in a staggered manner.

Since in the present embodiment a single fiber optic cable F isconnected to the plug connector 3 and a single connector assembly 1 isformed after mating with the receptacle connector 4, even if multiplesingle connector assemblies 1 are disposed on each of the top and bottomfaces of circuit board P in the electronic device, changes in the numberof, and the choice of placement locations for said single connectorassemblies 1 are done freely, which allows for an optimal designadaptable to various electronic devices.

As a result of imparting resilient member functionality only to the endterminals 66 of the receptacle connector 4 among the end terminals 52 ofthe plug connector 3 and the end terminals 66 of the receptacleconnector 4, a rearwardly directed biasing force is caused to act on theplug connector 3. However, embodiments involving said biasing force arenot limited thereto, and a rearwardly directed biasing force may becaused to act on the plug connector by imparting resilient memberfunctionality only to the end terminals of the plug connector or,alternatively, to the end terminals of both the plug connector and thereceptacle connector.

Although in the present embodiment the connector assemblies 1 aredisposed on the top and bottom faces in each of circuit board P andcircuit board Q, placing connector assemblies on both faces of thecircuit boards is not essential and connector assemblies may bedisposed, for example, only on the surface of either the top face or thebottom face.

The present invention is not limited to the embodiment described withreference to FIGS. 1 (A) to 10 and a number of variations are possible.For example, the inclined top faces 35A and inclined bottom faces 35B ofthe inclined protrusions 35 formed in the front half 31 of the plugconnector 3 do not have to be in substantially parallel planes andinclined with respect to the forward-backward direction X and the matingdirection Z as shown in FIG. 6 (A) and FIG. 6 (B), and it is sufficientfor only the inclined bottom faces 35′B to be inclined in the inclinedprotrusions 35′, as depicted in FIG. 11 (A) and FIGS. 12 (A) and 12 (B).In the embodiment depicted in FIG. 11 (A) and FIGS. 12 (A) and 12 (B),only the inclined bottom faces 35′B are inclined faces similar to thoseof FIG. 6 (A) and FIG. 6 (B), and the faces opposed thereto are notinclined and form front end faces 35′A that are perpendicular to theforward-backward direction X. In the upper section of theabove-mentioned inclined bottom faces 35′B, there are formed restrictedportions 35′B-1 that are similar to those of FIG. 6 (A) and FIG. 6 (B).As can be seen in FIG. 12 (A), when the plug connector 3 is mated withthe receptacle connector 4, in the same manner as in FIG. 6 (B), thefront end portion of the plug connector 3 is tilted downwardly and theinclined bottom faces 35′B of the inclined protrusions 35′ are placed ina nearly parallel orientation face-to-face with the restricting portions62B-1 forming the rear interior surfaces of the lead-in recesses 62B ofthe receptacle connector 4 and readily enter said lead-in recesses 62B.After mating of the plug connector 3 with the receptacle connector 4,the restricted portions 35′B-1 are placed in a face-to-face relationshipwith the restricting portions 62B-1 of the above-mentioned lead-inrecesses 62B, thereby restricting the position of the plug connector 3in the forward-backward direction X.

The advantage of such an embodiment is that the thickness between thefront end face 35′A and the inclined bottom face 35′B of theabove-mentioned inclined protrusions 35′ in the forward-backwarddirection X becomes larger than that of the inclined protrusions 35 ofFIGS. 6 (A) and 6 (B) and the strength of said inclined protrusions 35′is improved.

DESCRIPTION OF THE REFERENCE NUMERALS

-   1 Connector assembly-   3 Plug connector-   4 Receptacle connector-   20 Photoelectric conversion element-   21 Actuation device-   33 Lateral edge portion-   34 Front end edge portion-   35B-1, 35′B-1 Restricted portions-   51 Lateral terminals-   52 End terminals-   62B-1 Restricting portion-   65 Lateral terminals-   66 End terminals (resilient members)-   F Fiber optic cable-   X Forward-backward direction

What is claimed is:
 1. A connector assembly comprising: a plug connectorcomprising: a photoelectric conversion element configured to convertoptical signals to electrical signals, and electrical signals to opticalsignals; and an actuation device configured to drive said photoelectricconversion element; and a receptacle connector mated with said plugconnector, wherein the plug connector and receptacle connector areelectrically connected through mutual contact between terminals;wherein, in the plug connector, a front end side of a fiber optic cableconfigured to facilitate optical signal transmission is connected to,and rearwardly extends from, a rear end side of said plug connector andlateral terminals are arranged in each of a pair of lateral edgeportions that extend in a forward-backward direction; wherein at leastone of the plug connector and receptacle connector has provided thereinresilient members that generate a biasing force between the plugconnector and the receptacle connector in the forward-backwarddirection; and wherein a restricting portion, configured to provide alimiting value for the distance of relative displacement of the plugconnector with respect to the receptacle connector in a direction of thebiasing force under the action of the biasing force, is formed in thereceptacle connector, and another restricted portion is formed in theplug connector.
 2. The connector assembly according to claim 1, whereinthe resilient members are resilient end terminals arranged in a frontend edge portion of the plug connector or the receptacle connectorlocated on the front end side, and extending in a directionperpendicular to said forward-backward direction.
 3. The connectorassembly according to claim 1, wherein a direction perpendicular to theplane comprising an array direction of the resilient end terminals andthe array direction of the lateral terminals of the plug connector isused as the direction of mating of the plug connector and the receptacleconnector.